The purpose of this project is to cover basic and applied aspects of various pathogenic fungi including their morphology, taxonomy, pathogenicity, epidemiology, sexual life cycle and genetics. The topics of present interest include: 1) origin of the self-fertile isolates of Cryptococcus neoformans; 2) epidemiological and biological differences among four serotypes; 3) discovery of sexual state in Cryptococcus uniguttulatus. BIBLIOGRAPHIC REFERENCES: Kwon-Chung, K. J.: A new species of Filobasidiella, the sexual state of Cryptococcus neoformans, B and C serotypes. Mycologia 68: 942-946, 1976. Emmons, C. W., Binford, C. H., Utz, J. P. and Kwon-Chung, K. J.: Medical Mycology. Philadelphia, Lea and Febiger, 1977, 592 pp.